Man in the Middle Attacks: Here’s What You Need to Know

man in the middle attack

Though cybersecurity and data breaches are popular topics these days, many people don’t take the necessary precautions to keep their online activities secure. This leaves them vulnerable to cyberattacks, including man-in-the-middle attacks or MITMs. But what exactly is a MITM attack, and how can you prevent one? Read on to learn more about these kinds of cyberattacks and how to protect yourself from them.

What is a Man in the Middle Attack?

A man-in-the-middle attack is a kind of cyberattack where a hacker intercepts the communication between two parties. These kinds of attacks can target any type of online communication, such as email exchanges, social media messaging, or even website visits. The hacker can view your private data, including conversations, login credentials, or financial information. They can also send and receive data without your knowledge. Some types of online interactions that are often targets of MITM attacks are financial sites, connections involving public or private keys, and sites that require logins.

There are two phases to these attacks, interception and decryption. In the interception phase, hackers redirect your online activity through their network before it reaches the receiving party. The hacker can then see all the data you and your recipient exchange without your knowledge. After accessing the data, the hacker will proceed to decode it using a process called decryption.

These attacks can take many different forms, but here is an example of a common one. Imagine you want to view your checking account using an online banking system. You visit the site and enter your login information. But what you don’t know is that a hacker has inserted himself between you and the banking site. This means the hacker can see your login credentials, view all your financial information, and can access your bank account.

Different Types of Man in the Middle Attacks

There are a variety of ways an outside party can launch a MITM attack. Here are some of the most common ways the attacks are carried out:

Email Hijacking

Phishing Fishhook with PasswordIn email hijacking attacks, a hacker targets the email accounts of organizations like banks and financial institutions. They gain access to the personal accounts of employees and customers and monitor the transactions. When the opportunity arises, they use the bank’s email address to send their own instructions to customers. By following these instructions, the customers inadvertently send their money to the attackers instead of their bank.

Wi-Fi Eavesdropping

Another common type of MITM attack is Wi-Fi eavesdropping. In these cases, the attackers set up a Wi-Fi address that has a legitimate sounding name. Then they wait for users to connect to the Wi-Fi network. Once the users connect to the Wi-Fi, the hackers can access their devices, monitor their activity, and intercept their personal data.

Session Hijacking

A session hijacking attack takes place when you log into a website, often a banking site. A session is the period of time you spend logged into the site. These sessions are often targeted by hackers who want to obtain your information. There are various ways an attacker can access your session, but a common method is by stealing your browser cookies. These cookies store information such as your login credentials and online activity. By stealing your cookies, a hacker can easily log in to your account.

IP Spoofing

An Internet Protocol (IP) address is a unique number that identifies a network device. This number is linked to all your online activity and functions like a kind of electronic return address. In man-in-the-middle attacks, a hacker can spoof an IP address to make you think you’re interacting with a familiar website. In reality, you are interacting with the hacker, and possibly giving them access to your private information.

DNS Spoofing

Domain Name Server (DNS) spoofing is when a user is forced to access a fake website that is designed to look like a real one. If you are the target of DNS spoofing, you are likely to believe that you are visiting a legitimate site. But you are actually interacting with a hacker who is trying to divert traffic from the actual site and steal data like user login information.

HTTPS Spoofing

When browsing the internet or conducting business online, you will often see HTTPS in the URL. This indicates that the site is secure and you can use it safely. These sites have a special certificate key to keep them secure. However, there are hackers who provide a fake certificate key which tricks your browser into thinking you are visiting a secure site. This is known as HTTPS spoofing. The hacker sends you to an unsecured website and can monitor your activity and access your personal data.

How to Protect Yourself from MITM Attacks

Any internet user can be the target of a MITM attack. Protecting yourself can be challenging because your DNS servers are largely outside your control. Other parties manage these servers, such as the websites you visit, your Internet Service Provider (ISP), or your company’s IT department. If these servers are hacked, you might not find out in time. However, there are still a number of different steps you can take to protect yourself. Here are some of the most important ones:

Use an HTTPS Connection

While most websites used to transmit data over unsecured HTTP connections, a lot has changed in recent years. Now, most websites use HTTPS connections as a defense against cyberattacks. They are a bit more complicated and cost more to set up, but companies have found that the extra time and cost are worth it. Make sure you can see “HTTPS” in the URLs of the sites you visit, as well as a green lock icon. If you don’t see the HTTPS, add it manually. Then try reloading the site. If the lock is visible, this means your connection is now secured.

If you have your own website and still use HTTP, use an SSL/TLS Certificate to upgrade to the HTTPS protocol. This will establish a secure connection between your server and your customers’ computers. Once you set up your HTTPS connection, make sure that your servers are configured correctly for added protection.

Use HSTS for Added Security

While SSL/TLS Certificates are an important step to protect yourself, hackers can still find ways to get around them. Even if you type in an HTTPS request, attackers can still change the request to HTTP. This prevents encryption from taking place and leaves you vulnerable. For added security, consider using the web server directive HTTP Strict Transport Security or HSTS. This directive forces your browsers to connect to the HTTPS site and blocks content using HTTP protocols. It also prevents attackers from retrieving information from your browser cookies.

Keep Your Systems and Programs Up to Date

Hackers are constantly figuring out new ways to attempt MITM attacks and software developers often update programs to combat this. Make sure you are diligent about keeping your systems and programs up to date. This includes your web browser, your devices, and any apps on your computers and smartphones. Make sure to choose a good antivirus program and keep it updated as well to protect you against malware that hackers might use.

Be Careful With Wi-Fi Networks

This goes for both your home network and public Wi-Fi networks. Make sure your home Wi-Fi is secured and password protected. Your usernames and passwords should be strong, unique, and difficult to guess.

As for public Wi-Fi networks, proceed with caution. It’s best to avoid connecting to open networks, especially those without password protection. If you need to use one of these networks, avoid logging in and never use them to access financial accounts.

Use a VPN

VPN connectionWhen accessing a public Wi-Fi network, you should use a VPN to keep yourself and your data safe. Installing a VPN is an extremely effective way to keep your data secure. VPNs create an encrypted connection from a public internet or Wi-Fi network. This secures the data you send and receive while connected to the Wi-Fi network. If the network is compromised, a hacker will be unable to see what you’re doing online if you are using a VPN. This also means they will be unable to access your login credentials, financial data, and personal information.

Final Thoughts

Virtually anyone with an online presence can be the target of a MITM cyberattack. These attacks are essentially a digital form of eavesdropping where hackers can steal your personal or financial data, or even trick you into transferring money to them.

There are some basic steps internet users should take in order to protect themselves against these attacks. These include using a VPN for public Wi-Fi and internet connections, always using the HTTPS protocol, and keeping the software updated on all your devices. While it may not be possible to stop all hackers, by using precautions like these you can defend yourself against MITM attacks.

Tech journalist
Tove has been working for VPNoverview since 2017 as a journalist covering cybersecurity and privacy developments. Since 2019 she is's cybersecurity news coordinator.